In recent years, for the repair of damaged tissues, attempts have been made to transplant various cells. For example, for the repair of cardiac muscle tissue damaged due to an ischemic heart disease such as angina pectoris, or myocardial infarction, attempts have been made to use fetal cardiomyocytes, skeletal myoblasts, mesenchymal stem cells, cardiac stem cells, and ES cells (See, Haraguchi et al., Stem Cells Transl Med., 2012 February; 1 (2): 136-41).
As part of such attempts, a cell structure formed using a scaffold and a sheet-shaped cell culture obtained by forming cells into a sheet have been developed. (See JP-T-2007-528755).
Applications of sheet-shaped cell cultures to treatment have been studied focusing on regenerative medicine, including the use of a cultured epidermal sheet for skin damage due to a burn, the use of a sheet-shaped corneal epithelial cell culture for corneal damage, and the use of a sheet-shaped oral mucosa cell culture for the endoscopic excision of esophageal cancer.
Sheet-shaped cell cultures can be highly useful in regenerative medicine. However, they can be brittle as they are, and wrinkling, earing, and the like often occur during isolation from a culture medium or in the following operations. Thus, it can be extremely difficult to perform operations like transfer, storage, and implantation. In order to solve such problems, a method in which a fibrinogen liquid and a thrombin liquid are simultaneously sprayed onto a sheet-shaped cell culture to form a support layer containing fibrin on the sheet-shaped cell culture, thereby producing a laminate of a sheet-shaped cell culture and fibrin, has been attempted (See, JP-A-2011-172925).
With respect to the laminate of a sheet-shaped cell culture and fibrin described in JP-A-2011-172925, it has been found that when the laminate is isolated from a culture medium, there may be the case where the laminate tears, the case where isolation is not possible, or the case where the support layer comes off the sheet-shaped cell culture, making it impossible to obtain a complete laminate, for example. It has also been found that when the support layer is thickened to solve such problems, the cell function can be inhibited.